From the state of the art a large number of feed distribution systems are known. These systems have in common the fact that fixed feed dispensing points are present in the poultry house, and that the feed to be dispensed has to be conveyed from a central storage place to said feed dispensing points. For the conveyance of the feed a pipe conveyor system is present, which comprises one or more substantially horizontally directed feed conveyor pipes, which are disposed substantially parallel to each other, and which feed conveyor pipes are provided with means for conveying feed through them. The feed dispensing points are situated along the abovementioned feed conveyor pipes, and have regular distances between them.
A feeding device is disposed at each feed dispensing point. Such feeding devices are known in a wide variety of different embodiments. Most of them comprise a dish-shaped dispensing pan, a feed drop tube opening out above a central part of the pan in such a way that a volume of feed transported to the drop tube is distributed substantially evenly over the bottom surface of the pan. The pan can be directly connected to the drop tube by means of a suitable connection or indirect by means of several spoke-like plastic bars or carrying arms which are equally divided around the circumference of the device. In the last case the connection between the bars and the drop tube preferably is not rigid but is such that the height of the drop tube with respect to the pan can be altered in order to influence the amount of feed which enters the pan. Openings are present between the bars for the poultry to have access to feed distributed in the pan. Each opening is at least large enough for one animal to put his head through, but also may be large enough for accommodating the heads of several animals standing next to each other. See for example EP-0 421 553 or U.S. Pat. No. 5,875,733.
The conveyor pipes mostly have downwardly directed rectangular outlet openings at the positions of the feed dispensing points. The feeding devices in their entirety may be attached in such a way to the conveyor pipe that they are able to rotate somewhat around a longitudinal axis thereof. This rotatability helps to prevent injuries to the animals and damaging to the feeding devices themselves when bumping against the feeding devices. For obtaining this rotatability a cylindrical recess is formed into an assembly of a top end of the drop tube and a top support organ mounted thereto. In this attached position, the top end of the drop tube forms an inlet which is positioned directly underneath the outlet opening in the conveyor pipe.
This known type of feed distribution system has the disadvantage that it is somewhat difficult to clean.
When it is for example desired to clean the feeding devices of EP-0 421 553 with a high pressure hose, then it is very difficult and time consuming to remove all the dispensing pans from the devices in order to be able to properly clean them. Also it is very difficult and time consuming to place the pans back again after they have been cleaned. This is caused by the fact that a snapping connection between a lower ring of a grill assembly and the entire outer circumferential edge of the pan needs to be released and fastened again. After the pan has been removed it remains difficult if not say impossible to properly clean the inside of the drop tube. This can only be hosed clean by forcedly spraying water into a bottom end of the drop tube. However, for this the farmer needs to bend all the way down and he is likely to get all wet and dirty himself because of droplets splashing back. Also with this, a large part of the dirt is likely to be blown further upwards into the drop tube and the top support organ. Even worse it may happen that, because the outlet opening in the conveyor pipe is still open, the water and dirt are partly blown into the conveyor pipe. All in all this forms a risk that infection locations are formed where all kinds of bacteria and mould may start to grow. This may threaten the health of the animals. Blockades may be formed inside the conveyor pipe which may make it difficult or even impossible for enough feed to enter the pan at that specific feed dispensing point. Because of this some farmers even remove the entire feeding devices from the conveyor pipes, for which they need to disconnect the top support organs from the drop tubes. This is also a difficult and time-consuming operation.
With the feeding devices of U.S. Pat. No. 5,875,733 the removal of the dispensing pans is more easy since their dispensing pan is hingedly connected by means of a hinge joint to a lower ring of a grill assembly. Besides this hinge joint, the pan and the grill assembly are locked in position to each other by means of two clamping members. After the clamping members are released, the hinge joint makes it possible to quickly open the device by letting the pan rotate from its horizontal position to a downwardly hanging vertical position.
However, even then it is still difficult to clean the feeding devices. Firstly, when hinged open, the dispensing pan is freely hanging downwards and is unable to withstand the pressure from the cleaning jet of water. Thus the pan is somewhat difficult to clean and some farmers still take of the entire pan in order to be able to immerse it in a tank of disinfection fluid. Also it is emphasized that the inside of the drop tube can then still only be hosed clean by the farmer bending all the way down and then spraying water from underneath into the drop tube. Because of this infection hazards or blockades are still likely to occur inside the drop tubes and conveyor pipes.
With an alternative type of feed distribution system as shown in U.S. Pat. No. 6,532,895, which corresponds to WO 00/49857, it is known to mount the conveyor pipe rotatable around its longitudinal axis. During a first angular rotation of 90 degrees of the pipe the feeding pans maintain to hang freely downwards while the outlet openings in the pipe are rotated towards closed positions. During a subsequent second angular rotation of 90 degrees of the pipe the feeding pans are forced to co-rotate with the pipe and be moved from their downwardly hanging positions towards sideways projecting positions. In this sideways projecting positions the pans and the outer sides of the drop tubes can more easily be hosed clean. Because all the outlets in the conveyor pipe are simultaneously closed, it can also be ensured that the insides of the conveyor pipes remain dry.
However, it remains a problem to hose clean the insides of the drop tubes. For this it still would be necessary to first remove the dispensing pans and even then the farmer would be likely to forcedly blow at least some of the dirt merely further into the drop tubes towards their attachments with the conveyor pipes and into the top support organ. Furthermore this type of attachment places high demands on the partly rotation fixed connections between the feeding devices and the conveyor pipes. Also it requires a relative high force to centrally rotate the conveyor pipe with all the feeding devices hanging thereto by means of the farmer operating specific operating levers connected to the pipes.